JPS61272901A - Manufacture of thermal head - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION FIG. 1 is an explanatory diagram of a process for forming a heating resistor by modifying an electrical conductor. On the substrate 1, an electric conductor 3 for power supply is formed including a heat generating resistor forming part A and an electric conductor forming part B, B.

Next, ion implantation is performed in the heating resistor formation site A to modify the electrical conductor and convert its electrical properties into desired heating resistor characteristics. In this way, the heating resistor 2 is placed on the substrate 1.
A heating element part of the thermal head is produced, comprising: and electrical conductors 3.31 on both sides thereof. For example, the desired modification can be achieved by using aluminum as the electrical conductor and oxygen ions, silicon ions, chromium ions, nitrogen ions, etc. as the implants. Electrical conductors can be formed relatively thin.

FIG. 2 is an explanatory diagram of a process of forming a heating resistor by modifying the surface of a substrate. On the substrate 1, a heat generating resistor forming region A and an electric conductor forming region B are determined. Ion implantation is then performed at site A to modify the substrate surface and convert its electrical properties to the desired heating element properties. After this, the power supply electrical conductor 3.3' is formed. for example,
The desired modification can be achieved by making the substrate from a material whose main component is 810 and using aluminum ions, boron ions, phosphorus ions, etc. as implants.

In the embodiment of FIGS. 1 and 2, a protective layer as shown in FIG. 3 is provided. Further, after ion implantation, an activation process such as annealing can be performed. Annealing is a well-known technique used in semiconductor impurity diffusion processes, etc. to crystallize the amorphous state caused by the crystal lattice broken by ion implantation in a stable position while incorporating ions. It is.

Ion implantation technology uses a heated filament to evaporate metals and gases into plasma in a high electric field.
This is a technique that accelerates myions, draws them out in a beam, and causes them to collide with a target electrical conductor or substrate, and is widely used in the semiconductor field. The implantation area and implantation depth can be controlled with high accuracy.

A noteworthy feature of the specific example shown in FIG. 1 is that there is no surface step difference between the electrical conductor and the heating resistor. Conventionally, as shown in Fig. 3, when an electric conductor and a heating resistor are formed separately using different materials, a step is created between the surface of the electric conductor and the surface of the heating resistor, which reduces the efficiency of heat transfer to the printing medium. Along with this decrease, problems such as stress concentration occurring at corners and peeling of electrical conductors have been recognized. In the specific example shown in FIG. 1, since no step occurs, the above problem can be fundamentally solved. Depending on the type and amount of implanted ions, the heating resistor portion formed by ion implantation may swell higher than the electrical conductor portion, but in this case there is no problem because the heat transfer efficiency to the printing medium is improved.

Effects of the Invention t In the specific example shown in FIG. 1, the surface level difference between the electrical conductor and the thermal resistor does not occur, or the latter is raised, so that the efficiency of heat transfer to the printing medium is improved. Wear resistance life is improved.

2. In the specific example shown in FIG. 2, a heating resistor with a thickness of several to several hundred thicknesses can be easily formed, so that the electrothermal conversion efficiency is improved.

(5) Since the shape and dimensions of the heating resistor are determined by a highly accurate photoresist process, the dimensional accuracy of the heating resistor is improved and the uniformity of the resistance value of the thermal head is improved.

4. Since ion implantation is performed only in the necessary areas, there is no need for an etching process for the constituent material of the heating resistor. Therefore, variations due to etching are eliminated, and the uniformity of the resistance value is improved.

Additionally, there are no restrictions on the selectivity of the etchant with respect to the electrical conductor. This increases the degree of freedom in selecting the material for the electrical conductor. Furthermore, steps such as cleaning associated with the etching process are no longer necessary, simplifying the process.

5. Since the heating resistor can be formed using the minimum necessary area, the processing capacity of the device can be increased as well as reducing costs.

Example 1 An electrical conductor having a thickness of A1 was formed by DC sputtering on an alumina substrate provided with a glaze layer, and then Si, O, and N were ion-implanted into the region where the heating resistor was to be formed. The ion implantation conditions were as follows: Sl ion 40-100K
eV α3～lX101cndff1-”O ion 1
00 to 4! V 2)l Q"am""N ion 100Kev 6x101・c'x-"Example 2 Cr and B ions were implanted to a depth of 300 to 500 mm into the heating resistor formation site of the StO and back substrate, and then A1 An electrical conductor was formed. The ion implantation conditions were as follows: Cr I Do ~ 150 KeV α3 ~ lX
10"cIrL""2B 40 KeV
A thermal head was prepared from the products obtained in Examples 1 and 2 according to a conventional method. In the thermal head of Example 1, the print dot shape, which was conventionally rounded, is now close to rectangular and has a sharp shape, and the life of the wear-resistant layer has increased from 62 km to 81 km.
An improvement in performance was seen, with the length increasing by 13 times. As shown in FIG. 4, the thermal head of Example 2 achieves the same print density with about 8 inches lower printing power than the conventional product.

[Brief explanation of the drawing]

1 and 2 are explanatory diagrams illustrating the process of forming a heating resistor using ion implantation conditions according to the present method. FIG. 3 is a sectional view of an example of a conventional thermal head. FIG. 4 shows the print density of the thermal head from Example 2.
Shows the characteristics of printing power. 1: Substrate 2 = Heat generating resistor 3.31: Electric conductor 4: Protective layer Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Scope of Claims] 1) An electric conductor for power supply is formed on a substrate to extend to a heating resistor formation site, and ions are implanted into the heating resistor formation site to transform the electric conductor into a heating resistor. A method for manufacturing a thermal head characterized by modifying the body. 2) A method for manufacturing a thermal head, which comprises performing ion implantation on a heating resistor formation site on a substrate to modify the site on the substrate surface into a heating resistor, and then forming an electric conductor for power supply.